Stretching mechanism.



J. ALEXANDER.

STRETOHING MECHANISM.

APPLICATION FILED APR. 29, 1914.

Patented 00's. 27, 1914.

3 SHEETS-SHBET 1' w THMLNSBEMPQH Hw J. ALEXANDER. STRETGHING MECHANISM. APPLICATION FILED APR. 29, 1914.

Patented Oct. 27, 1914.-

'3 SHEETS-SHEET 2.

J". ALEXANDER.

STRBTGHING MECHANISM.

APPLICATION FILED APR.29,1914.

Patented Oct. 27, 1914.

3 SHEETS-$113111 3.

' To all whom it may concern tit UNITED STATES PATENT JULIAN ALEXANDER, OF PHILADELPHIA, PENNSYLVANIA.

s'rnn'rcnmo MECHANISM.

Be it known that I, J ULIAN ALExANDER, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Stretching Mechanism, of whichthe following is a specification.

With the devices heretofore used for stretching leather for use in the manufacture of driving belts it has been found difiicult or impossible to properly clamp and stretch irregularly shaped strips or butts without injuring them in such manner as to render comparatively large pieces practically valueless and one object of the present invention is to provide a device of the above class which under conditions of use shall properly perform its functions without injuring any but relatively small amounts of the material operated upon.

Further objects of the invention are the rovision of a stretching device which shall be durable, quickly and conveniently adjustable to suit it for attachment to pieces of widely varying shapes and which shall so hold such pieces that they may be properly dried.

'These objects and other advantageous ends I attain as hereinafter set forth, reference whic Figure 1 is a side elevation of a stretching device embodying my invention; Fig. 2 is a plan view of Fig. 1; Figs.,3 and 4 are enlarged sectional views taken respectively on beingkhad to the accompanying drawings in 'the lines aa and b-b Fig. 2; Figs. 5 to 10 inclusive are fragmentary views on an enlarged scale, illustrating details of the invention; and Fig. 11 is a diagrammatic view.

In the above drawings, 1 is a table or supporting structure preferably made in the form of a metallic frame work and carrying a slidable beam 2 provided on its lower face with a toothed-rack 3 and having adjacent one end a standard 2, the rack being engaged by a gear wheel 4, by which said beam may be moved in either of two directions longitudinally of the table. The table 1 is provided with brackets 5; each having a pocket 6, for a purpose hereafter noted. Standards 7 are secured to the table 1 and extend upwardly from the top thereof, as shown in Fig. 1; being connected by a cross bar 7.

A frame 8. consisting in the present in stance of two long cylindrical bars 9 and 10 Specification of Letters Patent.

-- Application filed April 29, 1914. serial No. 835,246.

Patented Oct. 2a, 1914.

connected adjacent their ends by two transverse cylindrical bars 11 and 12, has its bars 9 and 10 supported on the cross bar 7 a and its bar 11 resting within the pockets 6 of the brackets 5. This latter bar 11 forms a slideway for a. slide or carriage 13, which rests thereon. A hookbolt 14 (Fig. 3) extends under the bar 11 and projects upwardly through said carriage; its upper end being threaded for the reception of a nut 17 whereby a cam 15 mounted on said bolt is retained in position. Said cam has a radially projecting handle 16. The bolt 14 also'provides a pivotal support for two clamps 18 and 19, each consisting of two-pairs of plates 24-25 and 26-27 pivotally mounted on said bolt'and respectively fixed to bars or jaws 20, 21 and 22, 23, preferably of rectangular cross section. The jaws are provided with teeth 29 for biting into any material clamped between them.

Two other hook bolts 30 and 31 have their hooked ends extending under the bars 9 and 10 respectively and pass through carriages 35 which slidably engage said bars. The bolt 31 in addition serves as a pivotal support for two bearings 36 and 37 slidably engaged by the jaws 20 and 21 respectively and with them normally held apart by a coil spring 38, as shown in Figs. 7 and 8.

The bearing 36 has on its upper face a cam 39 formed to cooperate with a cam 40 pivotally mounted on the bolt 31 and held in place by anu-t threaded thereon. With this construction the turning of the cam 40 in one direction will cause the cam 39 to depress the bearing 36 and thereby move the jaw-20 toward the jaw 21 against the action of the spring 38. The cam 40 is provided with an operating handle or lever 41 and obviously itsoperation in moving the jaws to other also'causes the hooked end of the be t 31 and the carriage 35 to clamp the bar 10 of the frame 8. The bearings 36 and 37 have extensions 42 and 43 which act as stops to prevent the jamming or too close approach of the jaws 20 and 21 and also balance the pressure exerted on the jaws 20 and 22 to prevent the bending of the bolts 30 and 31. The stops 42? and 43* also perform the same function for the bolt 14. Similarly the bolt 80 has pivotally mounted on it two bearings 44 and 45 which form sliding supports for the jaws 22 and 23; the bearing 45 resting on the carriage 35 and the bearing 41 having on its upper face a mounted on bolts 57 carried'by the lower jaw and is, normally held awa --from the' same by springs 59. Each bolt has acamv cam 46.' This latter cooperates' with a cam 47 pivotally mounted on the bolt 30 and having a handle 49. r A spring 48 similar to the spring 38 tends to separate the bear ngs 44 and 45 and maintain the jaws 22 and-23 out of contact with each other. v

A spring 50 on the hook bolt 14 tends to keep the plates 25 and 26 separated andthus aids the springs 38 and 48 in normally keep ing-the jaws 20,21 and 22,23 apart-J The cam 005 crates with a cam 5lbetween itself andt e plate 24, so that whenit is .turned in one direction, theplates 24 and of their hooked ends and of the carriages '26 {will be actuated torespectively move the jaws 20 and 22 toward the jaws 21-and 23.

With the above combination, when j the cams 40,47 and-52 arer-in their released po sitions, the bolts 14, 'and 31 may be easily moved upon the bars of the frame 8 which they engage. When however any of these cams are turned to move. the jaws into clamping engagement with any material there will be a simultaneous clamping action upon the bars of the frame 8.

At the opposite end of he frame from the jaws 18 and 19 I provide-a clamp 54 having a lower jaw 55 extending across the frame 8 and slidably mounted on the bars'9 and 10 thereof. An upper jaw 56 ,is 'adjustably 6O rotatably mounted upon. its upper'end andthese cams cooperate with'cams 61 on the 11 per jaw .56, so that when they are turne 1n one direction the j aws;56 will be- -moved toward thejaws 55 against. the action of the springs 59. The cams 60 have handles 62 to facilitate their turning,' .and each bolt 57 has a nut 63 onits upper end. Theupper jaw 56 vhas upwardly projecting extensions 64 whichhave depresslons or recesses respectively in line with the recesses of the extensions 34 of the nuts 33 and said. parts are so arranged that their recesses may receive the frame 8 of otherstretching devices similar to that above described.

In order to hold the clamp 54 in any given osition I fix to the bars 9 and 10 of the rame 8 two toothed racks 66 and'at each end1of the lower jaw I mount a pawl v i; 65 in position to cooperate with said racks. These pawls are provided with handles 68 whereby they may be withdrawn from engagement with the racks when it is desired to slide the clamp 54 along the bars 9 and 10. For laterally stretchlng the material engaged by the other clamps I provide a ing jaw held to the head by a bolt 76. A rod 77, is mounted to freely slide within the tube 70, a nd has on one end a head 78 to which a jaw 81 is adjustably connected by a 'bolt 82, the adjacent faces of the head and jaw being provided with teeth 79 and 80 "as shown in Fig. 4.

a In using my invention one end of a leather strip or butt, usually cut off substantially at right angles to the long edges-thereof, is inserted-obetweenv the upper and lower jaws :of the clamp 54 and the cams 60 are turned soasto move downwardly the upper jaw 56 thereby causing it to grip said strip. The

bars 14, -30 and31'-, together with-the elements supported thereby are then slid along theirv respective bars of the frame 8 untilthe- 20, ,2l and 22, 23 are in positions adjacent and practically parallel with the irregular end portions of the strip to be stretched as s'hownin Figs. 2 and 3, and said portions are I inserted within said aws.

The cams 40, 7 .and 52 are then turned thus causing the jaws of the vclamps 18 and 19 to grip the i thenjclamped between the heads 71 and :78.

strip. The long edges of the leather are and their cooperating jaws-75 and 81 of the it as above described is then placed upon the table 1 so that the inner face of the lower jaw 55-..abuts upon. the standards 7 and the means of the gear vwheel. 4 thebeam 2 and ection 2 on the stretching beam 2. By I stretching clamp 69 as shown in Fig; 4 The frame having the leather strip secured to- 1 bar, 11 is engaged by the'standard or prowith. it'. the frame 8 is moved in the direc v .tion shown by the arrow Fig. '1, although the clamp '54 will remain stationary sincethe pawls 65 are so mounted as to slide over. 1 the teeth of the'racks 66. As a consequence the leather strip is longitudinally stretched and after it'has been subjected to sufficient tension the pawls 65 by engaging the teeth of the'racks 66 retain it in this, condition. y

Byrotating the gear wheel 4 in a. direction is movedin an opposite direction and the Any buckling or other irregularities in the by turning the threaded bar 72 of the stretch- 7,1 and 78 with their associated parts and this may be done either prior tothe removal longitudinal stretching of the-strip. a r

' Instead of having sets all operated in substantially the same .Forexample, instead of having the straight cross clamp 54 at one end of the frame I may have an additional set of clamps l8 and 19, in which-case the bar-12 no" opposite to that first indicated the beam 2 I frame with the leather strip in a stretched condition may be removed from the table; 1 1

surface of the leather strip may be removed .ing clamp 69 so as to move apart theheads of the frame from thetable or during the 7 but .one set .ofthe pivotal clamps 18 and 19 on the frame as' illustrated, I may employ two or more suchv could be employed as a slideway for the rod 14 and the slide or carriage 13. Also, in-

, stead of having two clamps pivoted together I may'have three or more sets pivoted to- E gether in link formation. In this latter case I could follow more closely the irregular edge of the leather, since the clamping jaws could be made relatively short and kept close to the irregular edge of the leather strip. j

Thevalue ofmy invention for stretching strips or butts of leather will be obvious from an inspection of Fig, 11, since if the ordinary straight clamps were employed to. grip both ends of the leather strip showntherein, it would be necessary to cut or a large piece m of triangular shape from the left hand end since such clamps would make transverse rooves 3 'y and z-z and only the part 0' the leather strip between such grooves could be used for the belt strips.

With my invention, instead of having the mark of the clamp, which is near the irregular end,-extending directly across the-leather as at y-y, it Will closely follow the irregular edge as shown by the lines A and B,

' Fig. 11, so that comparatively little of the leather will have to be cut awaysince all the leather between the line z,2 and the lines A-B is available for use. 'By'having the teeth of the clamps in the form of long ridges and by having the frame 8 open between the bars 9, 10, 11 and 12, air will have free access to all parts of the leather strip with the exception of the small portion which isheld between the teeth of the clamps. especially in 'the case of belt leather for it is important that all portions should dry evenly and at the same time.

I claim 1 1. The combination in a stretching device of a supporting structure; aplurality of angularly adjustable jawclamps thereon; means for pivotally connecting the jaws of each clamp; and a single device for simulthem to certain of Said bearings for said clamps ad ustably secured taneously actuating the jaws and causing them to be rigidly held to the supporting structure.

g 2. The combination of a supporting struc j ture; a plurality of pivotally connected sets of clamping aws; means slidable on said structure and formed to constitute a sliding bearing for the clamping jaws; with mechanism for securing said jaw bearing to the supporting structure. 4

3. The combination in a stretching device of a supporting structure having guideways;

a plurality of clamps; means pivotally connecting the clamps and adjustably securin uideways; an

i to the other of said guideways.

4. The combination in a stretching device of a supporting structure having guideways;

This is a very important feature,

for moving the awstogether and securing 'vicezof a'supporting structure; a 'of clamps; members slidable on said struca plurality of clamps; means for pivotally connecting the clamps ahd adjustably secur ing them to certain of said guideways; and

bearings adjustably mounted on others of slidable in said bearings. H 1

'5. The combination in a stretching device of a clamp havinga threaded opening and a said guideways; the clamps having jaws 'm tube communicating. therewith; a second clam a member having a portion slidablc within said tube and secured to said second clamp; with a threaded rod entering said threaded opening and contacting with said member to move the clamps apart.-

6. The combination in a stretching device of a supporting structure; a plurality of clamps each. having longitudinally extend- 'ing jaws means pivotally connecting the clamps .and slidably engaging the support ing structure; with bearing members slidably engaging the supportingstructure and each. having aslidewayfor the-jaws of a clamp. I 1, 7. The combination in a stretching device ofqa frame consisting of a number of bars joined together; a plurality of clamps;

means pivotally connectingsaid clam s and slidablysecuring them to one of sai bars; pivot members slidably secured to othersof said bars; withbearing members pivotally mounted on said pivot members, each forming a slideway for a clamp.

8. The combination in a stretching device of a supporting structure; a plurality of clamps having jaws; meansfonpivotally connecting the clamps; with common means formoving the jawstogether. and securing the clamps to the sup orting structure.

9. The combination m a stretching device of a supporting structure; a plurality of clamps having jaws; -'means for pivotally connecting the clamps; means for normally holding'th'e jaws apart; with common means them to the supporting structure;

10. The combination in a stretching deture and supporting said clamps; means pivotally connecting the clamps and secured to certain of said slidable members; and

-means for adjustably securing the members plurality of awclamps; canlurality latter bolts for securing them to the bars of the frame and for moving the jaws togethei.

' 12. The combination 1nv a stretching device of a frame'consistin of bars secured 5 together; a plurality of aw clam s; carriages slidable on said bars; a bolt orming a pivotal connection for the clamps and engaging one of said frame bars; means on said bolt for securing it to said frame bar and for moving together the jawsof the clamps; bearing members forming slideways for the jaws of the clamps; bolts extending through saidbearing members and engaging the bars of said frame; means on said latter bolts for securing them'to the bars of the frame and for moving-the jaws together; and springs on the bolts for normally keeping the clamp jaws apart.

13; The combination in a stretching device of a frame; a plurality of clamps having relatively mova 1e jaws; carriages slidable on said frame and supportlng the clamps; a bolt pivotally connecting said clamps and engaging the frame; bearing members forming slideways for the clamps; 7

a pivot bolts extending through said members and engaging the frame; cams on said clamps; and cams on said'pivot bolts placed to cooperate with thecams on the clamps to cause movement of the clamp jaws toward each other.

14. The combination in a stretching device of a frame; a plurality of jaw clamps; carriages slidable on said frame and supporting the clamps; a bolt pivotally connecting the clamps and engaging the frame; bearing members forming slideways for the clam s; pivot bolts extending through said mem ers and engaging the frame; cams on Y said bolts operable to move'the clamp jaws .1 together; and means on said bolts for grip- I I ping the frame when the cams are operated to move'said clamp jaws together.

In testimony whereof, I have signed my I named to this specification, in the presence of two subscribing Witnesses. Y 5

JULIAN ALEXANDER. v

Witnesses:

Aneus'rus B. Corrns, J os. H. KLEIN. 

